1. Technical Field
The field of the currently claimed embodiments of this invention relates to tracking systems and methods, and more particularly to a virtual rigid body optical tracking system and method.
2. Discussion of Related Art
Image-guided surgery systems are frequently used during surgery to provide surgeons with information support. For these systems to show their full capabilities and enable more advanced applications such as volume building or automated actuation, tools and devices must be registered together. An integral component to register these devices together is tracking. Conventional tracking is performed with electromagnetic (EM) or optical trackers. A sensor or marker is placed on the device, and the tracker reports the pose of the sensor or marker. In general, conventional tracking technologies are fairly accurate and can achieve sub-millimeter tracking errors. However, both EM and optical trackers have limitations. EM sensors do not require line of sight, but their accuracy is compromised in the presence of metal tools. This is a fairly significant limitation as many tools and devices must be avoided if one intends to use an EM tracker.
Optical trackers, on the other hand, do not suffer from metallic distortion. The first limitation for optical trackers are that they do require a line of sight between the optical tracker and the optical marker. The second limitation is that the size of the optical marker is limited by the size of the tool and the crowded surgical workspace. There has been some research in the design of optical markers [1]. However, there remains a need for improved optical tracking systems and methods.